Cracked heels form when thickened, dry skin on the bottom of your foot loses flexibility and splits under the pressure of your body weight. It’s one of the most common foot complaints, and while it often starts as a cosmetic nuisance, deep cracks can become painful and even prone to infection. The causes range from everyday habits like shoe choice to underlying medical conditions.
How Cracked Heels Actually Form
Your heel absorbs enormous force with every step. When the skin there is healthy and hydrated, it stretches and compresses without issue. But when friction, pressure, or dryness triggers the body’s protective response, the outer layer of skin starts overproducing tough, rigid cells. This thickened skin, or callus, is your body’s attempt at armor. The problem is that callused skin is stiff and poorly hydrated, so it can’t flex the way normal skin does.
Think of it like a piece of dry, brittle bread: step on it and it cracks. That’s essentially what happens to a callused heel under your full body weight. The sequence starts with microscopic breaks in the skin’s protective fat layer, followed by inflammation that drives even more thickening. As the skin becomes increasingly rigid, linear cracks (fissures) form and deepen with continued walking and standing. Once a fissure starts, every step pulls it open a little wider.
Shoes, Weight, and Standing
The most common everyday cause is footwear. Open-backed shoes like sandals, flip-flops, and mules allow your heel’s fat pad to expand sideways with each step. Your foot also slides around more inside these shoes, creating friction that accelerates callus buildup. Closed-back shoes with some cushioning keep the fat pad contained and reduce that lateral spreading.
Body weight plays a direct role. More weight means more downward force on the heel pad, which flattens it faster, reduces its natural cushioning, and increases the sideways tension that pulls skin apart. People who stand for long hours at work face the same issue simply through accumulated pressure over the day. Hard flooring, like concrete or tile, compounds the effect because it doesn’t absorb any of the impact your heel takes.
Going barefoot frequently also contributes. Without any shoe to contain the foot, the heel pad spreads freely, and the skin dries out faster from exposure to air.
Medical Conditions That Dry the Skin
Sometimes cracked heels are a signal that something else is going on in your body. Several medical conditions reduce the skin’s ability to stay moisturized from the inside out.
Diabetes is one of the most significant. High blood sugar can damage the nerves in your feet (peripheral neuropathy), which disrupts both blood flow and sweat gland function. Your sweat glands are actually a major source of moisture for the skin on your feet, so when they malfunction, the skin dries out quickly and cracks more easily. People with diabetes also heal more slowly, which means even minor fissures can become serious.
Thyroid disorders affect the skin through hormone regulation. When the thyroid underperforms, the metabolic processes that maintain tissue growth and skin hydration slow down. The result is dry, brittle skin throughout the body, but the heels show it first because they’re already under so much mechanical stress.
Skin conditions like eczema and psoriasis can also target the feet, creating patches of dry, flaky skin that are especially vulnerable to cracking. Athlete’s foot, a fungal infection, dries and damages the skin barrier in ways that make fissures more likely.
How Aging Changes Your Heels
Your skin naturally produces less oil as you get older. The sebaceous glands that keep skin lubricated become less active with age, leaving the skin drier and more prone to dehydration. Sweat gland activity also declines, and blood circulation to the feet decreases. Together, these changes make the outer layer of skin on your feet stiffer and less elastic. In areas already under constant pressure and friction, that stiffness translates directly into fissures and cracks. These cracks can also serve as entry points for bacteria and fungi, raising the risk of infections in older adults.
Nutritional Gaps That Show Up in Your Feet
Certain vitamin deficiencies can make your skin more vulnerable to cracking, though they’re rarely the sole cause. Vitamin E helps protect the collagen in your skin from aging-related damage and keeps it from drying out. Vitamin C supports moisture retention in skin cells, so a shortfall can lead to dehydration at the cellular level. Vitamin B3 deficiency is rarer but can cause a condition called pellagra, which produces dry, scaly skin on multiple parts of the body, including the heels.
If your diet is reasonably balanced, these deficiencies are unlikely to be your primary problem. But if you’re dealing with persistent cracked heels that don’t respond to moisturizing, it’s worth considering whether your nutrition could be a contributing factor.
When Cracks Become a Bigger Problem
Shallow surface cracks are mostly a cosmetic issue. They might catch on your socks or look rough, but they don’t typically cause pain. The concern grows when fissures deepen into the living layers of skin below the callus. At that point, you’ll feel a sharp or stinging pain when you put weight on your heel, and you might notice small amounts of bleeding.
Deep cracks create an opening in your skin’s barrier, which means bacteria can get in. Signs that a fissure has become infected include redness spreading beyond the crack itself, warmth, swelling, and discharge. For people with diabetes or compromised immune systems, even a small infected heel crack can escalate quickly and warrants prompt attention.
Treating and Preventing Cracked Heels
The cornerstone of treatment is consistent moisturizing with the right product. Urea-based creams are the gold standard for cracked heels because urea both hydrates and softens thickened skin. The concentration matters: creams with 2 to 10% urea work well for basic moisturizing and barrier repair, 10 to 30% provides moisturizing plus gentle exfoliation, and 40% urea (once prescription-only, now available over the counter) is used for heavy callus buildup and deeper fissures. For most people with mild to moderate cracking, something in the 20 to 25% range strikes a good balance.
Apply the cream after a shower or bath when the skin is still slightly damp, then cover your heels with socks to lock in moisture overnight. With consistent daily use, most people see noticeable improvement within about two weeks. Skipping days resets your progress, so regularity matters more than intensity.
For thicker calluses, a pumice stone or foot file can help reduce the buildup before you moisturize. Use it on damp skin and be gentle. Removing too much callus at once can leave the skin underneath raw and tender. The goal is gradual thinning over multiple sessions, not a single aggressive scrub.
Prevention comes down to three things: keeping the skin hydrated, reducing mechanical stress, and wearing supportive shoes. Closed-back shoes with cushioned insoles protect your heels from the friction and spreading that trigger callus formation. If you’re on your feet all day, gel heel cups can absorb some of the impact. Staying hydrated and maintaining a diet with adequate vitamins E, C, and B3 supports your skin’s ability to repair itself from the inside.